Mariner s compass



a UNITE STATES PATENT 1FFICE.

EDWARD SAMUEL RITCHIE, or BROOKLINE, MASSACHUSETTS.

MARINERS COM PASS.

SPECIFICATION forming part of Letters Patent No. 291,403, dated January 1, 1884.

Application filed September .25, 1883. No model.)

To aZZ whom it may concern.-

Be it known that I, EDWARD SAMUEL RITCHIE, of Brookline, in the county of Norfolk, of the Commonwealth of Massachusetts, have invented a new and useful Improvement in Mariners Compasses; and I do hereby declare the same to be described in the following specification and represented in the ac companying drawings, of which- Figures 1 and 2 are transverse sections of compass-bowls provided with my improvement, one of them showing it as applied to the compass-glasssustaining frame and bowl, and the other to the bottom of the bowl. Fig. 3 is a top View, and Fig. 4c a transverse section, of an expansive annulus, such as lose in carrying out my said invention. Fig. 5 is a transverse section of two of such annuli combined, as one or more of them may be used.

Fig. 6 is a section showing the two annuli as connected together and to the bowl and the frame for sustaining the glass disk or cover.

The invention relates to what are usually termed liquid-compasses, or those in which the bowl is filled with a liquid and the compass-card is immersed therein, the object of the improvement being not only to provide compensation for unequal expansion or 0011- traction of the bowl or liquid, induced by changes of temperature, but also to prevent any injurious pressure upon the bowl or its glass pane, as well as escape of liquid from or admission of air into the bowl, such as might result by reason of such changes of temperature. To this end I combine the annular I frame that supports theglass pane or cover at A, it being soldered at one edge or flange to the holder B, that sustains the glass pane G, and at the other to the bowl, the annulus being arranged between the said holder and bowl in manner as represented.

In Fig. 2 the elastic annulus A is represented as similarly applied to the body and constructed without any glass plate let or fixed in it. In each case there may or should extend around the connecting annulus, outwardly of it, an annular guard or protector, c; and, if desired or necessary, there may be another such guard extended from the bowl and arranged to project upward within the expansive annulus in manner as represented at c in Fig. 1. The holder of the glass pane is to be connected with the bowl by means of the expansive single or compound yielding annulus only, in order for the bowl or the holder to be free to move upward or downward, the annulus yielding to such movement, and at the same time preserving a liquid-tight joint or connection between the bowl and the holder of the glass pane or disk, or between the bottom and body of' the bowl, where the said bottom and body are connected by the annulus.

From the above it will be seen that a compass-bowl having a yielding annulus or its equivalent arranged in and applied to it in manner substantially as described can accommodate itself to the expansion or contraction of the liquid within it, or the metal of such body, so as to always remain full of such liquid, and this without danger to the glass disk or pane, or any other part of the bowl, being injured or cracked by any such change, due to any increase or decrease of atmospheric temperature or from other cause.

The yielding annulus, as shown in Figs. 3 and 4, is a thin flat ring having flanges at its edges, as represented. The ring may be perfectly fiat, or it may be somewhat conical or inclined transversely.

The compass described in the Unite-d States Patent No. 14,251 is not a liquid-compass, or one in which the card is surrounded by a liquid contained in the bowl, but is an ordinary mariners compass having no liquid in its bowl, and having to such bowl a domeshaped cover of glass, within which is a ring of metal, to fit upon or around the bowl, and around the said ring and between it and the glass cover is a ring of india-rubber. Thus it will be seen that to such a compass there I 2. The body of the bowl not only combined was noglass-pane holder, nor any connection with the bottom thereof, or with the glassof such to the body of the bowl by a yielding pane holder, by means of a yielding annulus, annulusof any kind, especially such as herei or by two or more yielding annuli, arranged inbefore described. and adapted as described, but provided with I olain1 one or more guards, as represented, arranged 1. In a liquid-compass, the body of the bowl with the yielding annulus or annuli, and for combined with the bottom thereof, or with the protection thereof, as set forth. the glass-pane holder, by means of a yielding EDWARD SAMUEL RITCHIE.

annulus, or by two or more yielding annuli, \Vitnesses: substantially and arranged and applied as set R. H. EDDY, forth. E. B. PRATT. 

